Vehicle body lower portion structure

ABSTRACT

A vehicle body lower portion structure includes: a lower frame member formed as a chamber that extends in a vehicle body longitudinal direction, having a guide portion at inner surfaces of wall portions that structure the chamber, the lower frame member being disposed at a vehicle body lower side; and a reinforcing member formed as a second chamber that extends in the vehicle body longitudinal direction, having a plurality of projections at outer surfaces of wall portions that structure the second chamber, the reinforcing member being provided within the chamber of the lower frame member in a state in which the plurality of projections are made to contact the guide portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. application Ser.No. 15/730,087 filed on Oct. 11, 2017, which claims priority under 35U.S.C. 119 from Japanese Patent Application No. 2016-233124 filed Nov.30, 2016. The disclosures of these prior applications are eachincorporated by reference herein in their entireties.

BACKGROUND Technical Field

Preferred embodiments relate to a vehicle body lower portion structure.

Related Art

Structures in which a reinforcing member that has a chamber structure isinserted into and disposed within a chamber of a lower frame member,such as a rocker or the like, are conventionally known (see, forexample, U.S. Pat. No. 8,702,161). A guide portion, which has guidesurfaces that prescribe the position of the reinforcing member, isprovided at the lower frame member, and the reinforcing member isinserted along the guide surfaces of this guide portion.

SUMMARY

However, in such a structure, at the time of inserting the reinforcingmember into the chamber of the lower frame member, the frictional forcebetween the reinforcing member and the guide surfaces at the guideportion is large, and there is the concern that it may be difficult toinsert the reinforcing member easily.

Namely, in such a structure, there is room for improvement from thestandpoint of the produceability of the lower frame member.

In consideration of the above circumstances, an object of preferredembodiments is to provide a vehicle body lower portion structure that,in a structure in which a reinforcing member having a chamber structureis inserted into and provided within the chamber of a lower framemember, can improve the produceability of the lower frame member.

A vehicle body lower portion structure of a first aspect of thedisclosure includes: a lower frame member formed as a chamber thatextends in a vehicle body longitudinal direction, and having a guideportion at inner surfaces of wall portions that structure the chamber,and the lower frame member being disposed at a vehicle body lower side;and a reinforcing member formed as a second chamber that extends in thevehicle body longitudinal direction, and having plural projections atouter surfaces of wall portions that structure the second chamber, andthe reinforcing member being provided within the chamber of the lowerframe member in a state in which the plural projections are made tocontact the guide portion.

In accordance with the vehicle body lower portion structure of the firstaspect, the plural projections, which are formed at the outer surfacesof the wall portions that structure the second chamber of thereinforcing member, contact the guide portion that is formed at theinner surfaces of the wall portions that structure the chamber of thelower frame member. Namely, the reinforcing member is inserted into andprovided within the chamber of the lower frame member while the pluralprojections are made to contact the guide portion. Accordingly, thefrictional force at the time of insertion is reduced as compared with astructure in which the reinforcing member is inserted into and providedwithin the chamber of the lower frame member while the outer surfaces ofthe wall portions of the reinforcing member are made to contact theguide portion. Accordingly, the produceability of the lower frame memberis improved.

Further, in a vehicle body lower portion structure of a second aspect ofthe disclosure, in the first aspect, a battery installed on a batteryframe is configured to be disposed at a vehicle transverse directioninner side of the lower frame member, and, in a side view seen in avehicle transverse direction, at least a portion of the reinforcingmember overlaps with the battery or the battery frame.

In accordance with the vehicle body lower portion structure of thesecond aspect, in the side view seen in the vehicle transversedirection, at least a portion of the reinforcing member overlaps withthe battery or the battery frame. Accordingly, the collision load thatis inputted at the time of a side collision of the vehicle istransmitted to the battery or the battery frame via the reinforcingmember, as compared with a structure in which the reinforcing memberdoes not overlap with the battery or the battery frame in a side viewseen in the vehicle transverse direction. Accordingly, deformation ofthe vehicle cabin is suppressed, and the collision safety performance atthe time of a side collision of the vehicle is improved.

In a vehicle body lower portion structure of a third aspect of thedisclosure, in the second aspect, the battery frame has a cross memberthat extends in the vehicle transverse direction and the battery issectioned into front and rear portions by the cross member, and at leasta portion of the reinforcing member is configured to overlap with thecross member in the side view seen in the vehicle transverse direction.

In accordance with the vehicle body lower portion structure of the thirdaspect, at least a portion of the reinforcing member overlaps with thecross member of the battery frame, in the side view seen in the vehicletransverse direction. Accordingly, the collision load that is inputtedat the time of a side collision of the vehicle is transmitted to thecross member of the battery frame via the reinforcing member, ascompared with a structure in which the reinforcing member does notoverlap with the cross member of the battery frame in a side view seenin the vehicle transverse direction. Accordingly, deformation of thevehicle cabin is further suppressed, and the collision safetyperformance at the time of a side collision of the vehicle is improved.

In a vehicle body lower portion structure of a fourth aspect of thedisclosure, in the first through third aspects, in a front view seen inthe vehicle body longitudinal direction, the reinforcing member isformed in a rectangular shape whose length direction is along a vehicletransverse direction, and the reinforcing member has one or moresectioning walls that section an interior of the second chamber of thereinforcing member into plural spaces.

In accordance with the vehicle body lower portion structure of thefourth aspect, in the front view seen in the vehicle body longitudinaldirection, the interior of the second chamber of the reinforcing member,which is formed in a rectangular shape whose length direction is alongthe vehicle transverse direction, is sectioned into plural spaces by oneor more sectioning walls. Accordingly, deformation that is such that thereinforcing member opens wide is suppressed, as compared with areinforcing member at which a sectioning wall is not provided within thesecond chamber thereof. Accordingly, the buckling stress of thereinforcing member with respect to the collision load that is inputtedat the time of a side collision of the vehicle is increased.

In a vehicle body lower portion structure of a fifth aspect of thedisclosure, in the fourth aspect, in the front view seen from thevehicle body longitudinal direction, the plural projections are formedat same positions in the vehicle transverse direction as positions atwhich vehicle transverse direction side walls of the reinforcing memberand vehicle body vertical direction end portions of the one or moresectioning wall are located.

In accordance with the vehicle body lower portion structure of the fifthaspect, in the front view seen in the vehicle body longitudinaldirection, the plural projections are formed at the same positions inthe vehicle transverse direction as the positions at which the vehicletransverse direction side walls of the reinforcing member and thevehicle body vertical direction end portions of the one or moresectioning wall are located. Accordingly, when the reinforcing memberdeforms so as to open wide, reaction force from the guide portion iseffectively obtained via the projections, as compared with a structurein which the plural projections are formed at different positions in thevehicle transverse direction from the positions at which the vehicletransverse direction side walls of the reinforcing member and thevehicle body vertical direction end portions of the one or moresectioning wall are located. Accordingly, the buckling stress of thereinforcing member with respect to the collision load that is inputtedat the time of a side collision of the vehicle is increased more.

In a vehicle body lower portion structure of a sixth aspect of thedisclosure, in the fourth aspect or the fifth aspect, in the front viewseen in the vehicle body longitudinal direction, at least a vehicletransverse direction innermost space among plural spaces that aresectioned by the sectioning wall is made to be smallest among the pluralspaces.

In accordance with the vehicle body lower portion structure of the sixthaspect, in the front view seen in the vehicle body longitudinaldirection, at least the vehicle transverse direction innermost space,among the plural spaces that are sectioned by the sectioning wall, ismade to be smallest among the plural spaces. Accordingly, at the vehicletransverse direction outer side portion with respect to the vehicletransverse direction innermost side portion, the reinforcing member hasa portion where the rigidity is low. The deformation mode of thereinforcing member toward the vehicle transverse direction inner sidedue to the collision load that is inputted at the time of a sidecollision of the vehicle is stabilized.

In a vehicle body lower portion structure of a seventh aspect of thedisclosure, in the first through sixth aspects, the lower frame memberand the guide portion are formed integrally.

In accordance with the vehicle body lower portion structure of theseventh aspect, the lower frame member and the guide portion are formedintegrally. Accordingly, the produceability of the lower frame member isimproved more, as compared with a case in which the lower frame memberand the guide portion are structured by separate bodies.

In a vehicle body lower portion structure of an eighth aspect of thedisclosure, in the first through seventh aspects, the lower frame memberhas an upper side chamber portion and a lower side chamber portion, andat least a portion of the guide portion is structured by a partitioningwall that partitions the upper side chamber portion and the lower sidechamber portion.

In accordance with the vehicle body lower portion structure of theeighth aspect, at least a portion of the guide portion is structured bythe partitioning wall that partitions the upper side chamber portion andthe lower side chamber portion of the lower frame member. Accordingly,the produceability of the lower frame member is improved, as comparedwith a case in which the guide portion is not structured by thepartitioning wall. Further, the rigidity of the lower frame member isimproved by the partitioning wall.

In a vehicle body lower portion structure of a ninth aspect of thedisclosure, in the eighth aspect, the lower frame member has, betweenthe upper side chamber portion and the lower side chamber portion, anintermediate chamber portion that is structured to include thepartitioning wall, and the reinforcing member is provided within a thirdchamber at the intermediate chamber portion.

In accordance with the vehicle body lower portion structure of the ninthaspect, the intermediate chamber portion is formed so as to include thepartitioning wall, between the upper side chamber portion and the lowerside chamber portion of the lower frame member. The reinforcing memberis provided within the third chamber at this intermediate chamberportion. Accordingly, the buckling stress of the lower frame member withrespect to the collision load that is inputted at the time of a sidecollision of the vehicle is increased, and deformation of the vehiclecabin is suppressed.

In a vehicle body lower portion structure of a tenth aspect of thedisclosure, in the eighth aspect or the ninth aspect, a maximum width ofthe upper side chamber portion in the vehicle transverse direction isshorter than a length of the reinforcing member in the vehicletransverse direction.

In accordance with the vehicle body lower portion structure of the tenthaspect, the maximum width of the upper side chamber portion in thevehicle transverse direction is made to be shorter than the length ofthe reinforcing member in the vehicle transverse direction. Accordingly,the space of the vehicle cabin in the vehicle transverse direction isbroadened, and the flexibility in the design of the vehicle cabin layoutincreases.

In a vehicle body lower portion structure of an eleventh aspect of thedisclosure, in the first through tenth aspects, the lower frame memberis structured by a rocker that extends in the vehicle body longitudinaldirection, and by an energy absorbing member that is formed as a fourthchamber that extends in the vehicle body longitudinal direction, andthat is disposed at a vehicle body lower side of the rocker.

In accordance with the vehicle body lower portion structure of theeleventh aspect, the lower frame member is structured by the rocker andthe energy absorbing member that is disposed at the vehicle body lowerside of the rocker. Namely, the reinforcing member is provided at therocker or the energy absorbing member. Accordingly, the buckling stressof the lower frame member with respect to the collision load that isinputted at the time of a side collision of the vehicle is increasedmore, and deformation of the vehicle cabin is suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments will be described in detail based on the followingfigures, wherein

FIG. 1 is a plan view of a vehicle that has a vehicle body lower portionstructure relating to a present embodiment;

FIG. 2 is a cross-sectional view seen in the direction of the X-X arrowof FIG. 1, showing a vehicle body lower portion structure relating to afirst embodiment;

FIG. 3 is a partial, enlarged sectional view of FIG. 2, showing thevehicle body lower portion structure relating to the first embodiment;

FIG. 4 is a cross-sectional view that corresponds to FIG. 3 and shows avehicle body lower portion structure relating to a second embodiment;

FIG. 5 is a cross-sectional view that corresponds to FIG. 3 and shows avehicle body lower portion structure relating to a third embodiment;

FIG. 6 is a cross-sectional view that corresponds to FIG. 3 and shows avehicle body lower portion structure relating to a fourth embodiment;

FIG. 7 is a cross-sectional view that corresponds to FIG. 3 and shows avehicle body lower portion structure relating to a fifth embodiment;

FIG. 8 is a cross-sectional view that corresponds to FIG. 2 and shows avehicle body lower portion structure relating to a sixth embodiment; and

FIG. 9 is a cross-sectional view that corresponds to FIG. 2 and shows avehicle body lower portion structure relating to a seventh embodiment.

DETAILED DESCRIPTION

Embodiments relating to the present disclosure are described in detailhereinafter on the basis of the drawings. Note that, for convenience ofexplanation, arrow UP that is shown appropriately in the respectivedrawings is the vehicle body upward direction, arrow FR is the vehiclebody frontward direction, and arrow LH is the vehicle body leftwarddirection. Further, in the following description, when vertical,longitudinal, and left-right directions are used without beingspecified, they refer to the vertical of the vehicle body verticaldirection, the longitudinal of the vehicle body longitudinal direction,and the left and the right of the vehicle body left-right direction (thevehicle transverse direction).

First Embodiment

First, a vehicle body lower portion structure 10 relating to a firstembodiment is described. As shown in FIG. 1, at a vehicle 12 that isequipped with the vehicle body lower portion structure 10 relating tothe present embodiment, a battery 14 is installed at the entire surfacebeneath the floor of the vehicle cabin in order to extend the drivabledistance. The battery 14 is structured by plural (e.g., 8 rows in thevehicle body longitudinal direction×two rows in the vehicle transversedirection) storage batteries. The exterior of the battery 14 is a casethat is shaped as a rectangular box and that is relatively hard suchthat it is difficult to plastically deform even if collision load isinputted thereto.

Further, as shown in FIG. 1 and FIG. 2, the battery 14 is installed onthe top surface of a battery frame 16 that is shaped as a tray. Aperipheral wall 17 stands upright at the outer peripheral portion of thebattery frame 16. Plural cross walls 15, which serve as cross membersand extend in the vehicle transverse direction, stand erect at the topsurface of the battery frame 16 at intervals in the vehicle bodylongitudinal direction. The respective cross walls 15 stand erect at aheight that is slightly lower than that of the peripheral wall 17. Thestorage batteries are disposed so as to be separated four-by-four by therespective cross walls 15 (see FIG. 1).

Rockers 20, which serve as a left-right pair of lower frame members, aredisposed at the vehicle transverse direction outer sides of the battery14. In other words, the battery 14 that is mounted on the battery frame16 is disposed at the vehicle transverse direction inner sides of therockers 20. Note that, as shown in FIG. 2, the top surfaces of flangeportions 16A, which project-out toward the vehicle transverse directionouter sides from the bottom surface of the peripheral wall 17 of thebattery frame 16, are joined to the bottom surfaces of bottom walls 24Dof lower side chamber portions 24, which are described later, of therockers 20.

The rockers 20 are formed as substantially rectangular chamber thatextend in the vehicle body longitudinal direction, by extrusion moldingof a light-weight metal material (e.g., an aluminum alloy). The rocker20 is partitioned into an upper side chamber portion 22 and the lowerside chamber portion 24 by a partitioning wall 26 that is shaped as aflat plate and functions as a guide portion 25 at the time of insertinga reinforcing member 30 that is described later.

In a front view seen from the vehicle body front side, in other word thefront view is seen in the vehicle front-rear direction (the same isapplied hereafter), and shown in FIG. 2, the vehicle transversedirection outer side end of the lower side chamber portion 24 is flushwith the vehicle transverse direction outer side end of the upper sidechamber portion 22. However, the vehicle transverse direction inner sideend of the lower side chamber portion 24 projects-out further toward thevehicle transverse direction inner side than the vehicle transversedirection inner side end of the upper side chamber portion 22.

In other words, in the state in which the respective vehicle transversedirection outer side ends of the upper side chamber portion 22 and thelower side chamber portion 24 are flush with one another, the maximumwidth of the upper side chamber portion 22 is made to be shorter thanthe maximum width of the lower side chamber portion 24 in the vehicletransverse direction or the length, in the vehicle transverse direction,of the reinforcing member 30 that is described later.

Further, a flange portion 24A that projects out toward the vehicletransverse direction inner side is formed integrally with a top wall 24Uthat is at the vehicle transverse direction inner side end portion ofthe lower side chamber portion 24. The top wall 24U projects out furthertoward the vehicle transverse direction inner side than the vehicletransverse direction inner side end of the upper side chamber portion22. A vehicle transverse direction outer side end 18A of a floor panel18 that structures the floor of the vehicle cabin is joined to the topsurface of the flange portion 24A or to the top surface of the top wall24U that includes the flange portion 24A.

Note that the top wall 24U at the vehicle transverse direction innerside end of the lower side chamber portion 24 is at a height positionthat is the same as the partitioning wall 26. Namely, the top wall 24Uand the flange portion 24A are disposed on a line of extension of thepartitioning wall 26 toward the vehicle transverse direction inner side.Further, the battery 14 is disposed further toward the vehicle bodylower side than the floor panel 18 with a gap D (see FIG. 2)therebetween.

In the front view, a flange portion 22A, which is shaped as a flat plateand extends in the vehicle body longitudinal direction with the vehicletransverse direction being the normal direction thereof, is formedintegrally with the substantially central portion in the vehicletransverse direction of the top surface (the outer surface) of a topwall 22U of the upper side chamber portion 22. Further, an inclinedportion 24B, which is inclined upwardly toward the vehicle transversedirection outer side, is formed at the vehicle transverse directionouter side and at the lower end portion of the lower side chamberportion 24. The inclined portion 24B integrally connects an outer sidewall 24T and the bottom wall 24D that are described later.

Moreover, guide walls 28, which are rib-shaped and serve as the guideportion 25 and that project-out into the chamber along the vehicletransverse direction respectively, are formed integrally at the innersurface of the outer side wall 24T and the inner surface of an innerside wall 24N. The outer side wall 24T and the inner side wall 24N forma part of the chamber of the lower side chamber portion 24. Namely, theguide portion 25 relating to the present embodiment is structured by thepartitioning wall 26 and the guide walls 28.

Note that the projecting length along the vehicle transverse directionof the guide walls 28 is not particularly limited, but, for example, isa length of an extent that is such that the guide walls 28 can support,at least from the vehicle body lower side, projections 34 that areformed at the vehicle transverse direction both end portions of thebottom outer surface of a bottom wall 30D of the reinforcing member 30that is described later.

Further, the reinforcing member 30 that is for improving the rigidity ofthe rocker 20 is provided by being inserted from the vehicle body frontside or the vehicle body rear side into the region (hereinafter called“insertion portion E”) at the interior of the chamber of the lower sidechamber portion 24 which region is surrounded by the partitioning wall26, the outer side wall 24T, a portion of the inner side wall 24N, andthe guide walls 28.

As shown in FIG. 3, the reinforcing member 30 is formed as a rectangularchamber that extends in the vehicle body longitudinal direction, byextrusion molding of a light-weight metal material (e.g., an aluminumalloy). The length direction of this rectangular chamber is along thevehicle transverse direction, in the front view. Further, plural (e.g.,four) sectioning walls 32, which section the interior of the chamber ofthe reinforcing member 30, are formed integrally with the reinforcingmember 30.

The respective sectioning walls 32 are formed in the shapes of flatplates that extend in the vehicle body longitudinal direction with thevehicle transverse direction being the normal direction thereof, and aredisposed so as to section the interior of the chamber of the reinforcingmember 30 into, for example, uniform intervals in the vehicle transversedirection. Further, the plural projections 34 that respectively extendin the vehicle body longitudinal direction are formed integrally withthe top surface (the outer surface) of a top wall 30U and the bottomsurface (the outer surface) of the bottom wall 30D that serve as wallportions that are flat-plate-shaped and structure the chamber of thereinforcing member 30.

In detail, in the front view, each of the projections 34 is formed so asto, with the top surface of the top wall 30U or the bottom surface ofthe bottom wall 30D, form a substantially isosceles triangular shape ora substantially equilateral triangular shape. The projections 34 arestructured such that only the peak portions thereof contact the bottomsurface of the partitioning wall 26 and the top surfaces of the guidewalls 28. Namely, the reinforcing member 30 is provided by beinginserted into the insertion portion E, which is formed within thechamber of the lower side chamber portion 24 of the rocker 20, whileonly the peak portions of the plural projections 34 are made to contactthe bottom surface of the partitioning wall 26 and the top surfaces ofthe guide walls 28.

Further, in particular the projections 34, which are formed at thevehicle transverse direction both end portions of the bottom surface ofthe bottom wall 30D of the reinforcing member 30, are disposed in statesof being supported on the top surfaces of the guide walls 28 from thevehicle body lower side. Note that the respective projections 34 aredisposed at the same positions in the vehicle transverse direction withrespect to positions at which the vehicle transverse direction both endportions of the top surface of the top wall 30U and the bottom surfaceof the bottom wall 30D of the reinforcing member 30 are located. Inother word, the respective projections 34 are disposed at the samepositions with respect to the vehicle body vertical direction both endportions of an outer side wall 30T and an inner side wall 30N of thereinforcing member 30, and with respect to the vehicle body verticaldirection both end portions of the sectioning walls 32.

Operation of the vehicle body lower portion structure 10, which relatesto the first embodiment and is structured as described above, isdescribed next.

As described above, the reinforcing member 30 is provided by beinginserted into the insertion portion E while the peak portions of theplural projections 34, which are formed integrally with the top surfaceof the top wall 30U and the bottom surface of the bottom wall 30D of thereinforcing member 30, are made to contact the bottom surface of thepartitioning wall 26 and the top surfaces of the guide walls 28.Accordingly, the frictional resistance of the reinforcing member 30 withrespect to the bottom surface of the partitioning wall 26 and the topsurfaces of the guide walls 28 can be lessened as compared with a casein which the reinforcing member 30 is inserted into the insertionportion E while the top surface of the top wall 30U and the bottomsurface of the bottom wall 30D thereof are made to contact the bottomsurface of the partitioning wall 26 and the top surfaces of the guidewalls 28.

Namely, in accordance with the present embodiment, the frictional forceat the time of inserting the reinforcing member 30 into the rocker 20can be reduced, and the produceability of the rocker 20 can be improved.Moreover, because the rocker 20 and the partitioning wall 26 and theguide walls 28 are formed integrally, the produceability of the rocker20 can be further improved as compared with a case in which the rocker20 and the partitioning wall 26 and the guide walls 28 are formed asseparate bodies.

Further, at least a portion of the guide portion 25 is formed by thepartitioning wall 26 that partitions the upper side chamber portion 22and the lower side chamber portion 24 of the rocker 20. Therefore, theproduceability of the rocker 20 can be further improved as compared witha case in which the guide portion 25 is not formed by the partitioningwall 26. Note that, owing due to partitioning wall 26, there is also theadvantage that the rigidity of the rocker 20 with respect to loadinputted from the vehicle transverse direction outer side can beimproved.

Further, in the front view, the interior of the chamber of thereinforcing member 30 is partitioned into plural spaces by the pluralsectioning walls 32. Therefore, the rigidity of the reinforcing member30 with respect to the collision load that is inputted at the time of aside collision of the vehicle 12, i.e., the buckling stress, can beincreased as compared with that of a reinforcing member at which thesectioning members 32 are not provided within the chamber thereof inwhich the lengths in the vehicle transverse direction of the top wall30U and the bottom wall 30D are not divided by the sectioning walls 32(a structure not illustrated).

Further, in the front view, the plural projections 34 are formed at thesame positions in the vehicle transverse direction as positions at whichthe vehicle body vertical direction both end portions of the sectioningwalls 32, and the vehicle body vertical direction both end portions ofthe outer side wall 30T and the inner side wall 30N are located.Therefore, reaction force from the partitioning wall 26 and the guidewalls 28 is effectively obtained via the projections 34 at the time whenthe reinforcing member 30 deforms so as to open wide (the time when thetop wall 30U plastically deforms toward the vehicle body upper side andthe bottom wall 30D plastically deforms toward the vehicle body lowerside), as compared with a structure in which the plural projections areformed at positions that are different, in the vehicle transversedirection, from the positions at which the vehicle body verticaldirection both end portions of the sectioning walls 32 and the vehiclebody vertical direction both end portions of the outer side wall 30T andthe inner side wall 30N are located.

Accordingly, the buckling stress of the reinforcing member 30 withrespect to the collision load that is inputted at the time of a sidecollision of the vehicle 12 can be further increased. Namely, inaccordance with the vehicle body lower portion structure 10 relating tothe present embodiment, both an improvement in the produceability of therocker 20 and an improvement in the rigidity (an improvement in theefficiency of the energy absorption at the time of a side collision ofthe vehicle 12) of the rocker 20 and the reinforcing member 30 can berealized simultaneously.

Further, the maximum width of the upper side chamber portion 22 in thevehicle transverse direction is made to be shorter than the maximum withof the lower side chamber portion 24 in the vehicle transverse directionand the length of the reinforcing member 30 in the vehicle transversedirection, in the state in which the vehicle transverse direction outerside end portion of the upper side chamber portion 22 and the vehicletransverse direction outer side end portion of the lower side chamberportion 24 are flush with one another.

Accordingly, the length of the floor panel 18 in the vehicle transversedirection can be made to be long, and the vehicle cabin space can bebroadened by that much, as compared with a structure in which, forexample, the maximum width of the upper side chamber portion 22 is madeto be the same length as the maximum length of the lower side chamberportion 24 and the length of the reinforcing member 30 in the vehicletransverse direction.

Further, in a side view seen from a vehicle body right side or a vehiclebody left side, in other word the side view is seen in the vehicletransverse direction (the same is applied hereafter), at least a portionof the reinforcing member 30 overlaps with the battery 14 or the batteryframe 16. Accordingly, the collision load that is inputted at the timeof a side collision of the vehicle 12 is efficiently transmitted via thereinforcing member 30 to the battery 14 or the battery frame 16, ascompared with a structure in which the reinforcing member 30 does notoverlap with the battery 14 or the battery frame 16 in the side view.Accordingly, deformation of the vehicle cabin can be suppressed, and thecollision safety performance at the time of a side collision of thevehicle 12 can be improved.

Note that, as described above, the exterior of the battery 14 in thepresent embodiment is structured by a relatively hard case, and thebattery 14 is made to be a structure that is difficult to plasticallydeform even if collision load is inputted thereto. Accordingly, even ifcollision load is inputted to the battery 14, the interior of thebattery 14 can be protected.

Namely, in accordance with the present embodiment, the collision loadthat is inputted at the time of a side collision of the vehicle 12 canbe transmitted to the battery 14. Therefore, a load transmitting memberfor transmitting the collision load can be made to be light-weight orcan be omitted. Accordingly, a good load resistance performance can beobtained without increasing the weight of the vehicle 12.

Second Embodiment

The vehicle body lower portion structure 10 relating to a secondembodiment is described next. Note that regions that are equivalent tothose of the above-described first embodiment are denoted by the samereference numerals, and detailed description thereof (includingdescription of common operation) is omitted as appropriate.

As shown in FIG. 4, in the vehicle body lower portion structure 10relating to the second embodiment, at the reinforcing member 30, cornerportions 31 formed at the vehicle body vertical direction both endportions, at which the bottom surface of the top wall 30U and the topsurface of the bottom wall 30D, and inner surfaces of the sectioningwalls 32, intersect one another, are formed in arc-shapes in the frontview. The inner surfaces of the sectioning walls 32 face toward thevehicle transverse direction inner side or face toward the vehicletransverse direction outer side. The plate thickness of the portions ofthe top wall 30U and the bottom wall 30D is increased at the respectivecorner portions 31. Namely, the rigidity of the top wall 30U and thebottom wall 30D that include the respective corner portions 31 isimproved.

Accordingly, in addition to the operation of the vehicle body lowerportion structure 10 relating to the above-described first embodiment,when the reinforcing member 30 deforms so as to open wide at the time ofa side collision of the vehicle 12, the reaction force from thepartitioning wall 26 and the guide walls 28 is more effectively obtainedvia the projections 34. Accordingly, the buckling stress of thereinforcing member 30 with respect to the collision load that isinputted at the time of a side collision of the vehicle 12 can beincreased more. Note that, at the reinforcing member 30, the cornerportions 31, at which the bottom surface of the top wall 30U and the topsurface of the bottom wall 30D, and the inner surfaces of the outer sidewall 30T and the inner side wall 30N, intersect one another, also areformed in arc-shapes in a front view seen from the vehicle bodylongitudinal direction.

Third Embodiment

The vehicle body lower portion structure 10 relating to a thirdembodiment is described next. Note that regions that are equivalent tothose of the above-described first embodiment and second embodiment aredenoted by the same reference numerals, and detailed description thereof(including description of common operation) is omitted as appropriate.

As shown in FIG. 5, in the vehicle body lower portion structure 10relating to the third embodiment, in the front view, plural (e.g., five)spaces S1 through S5 are sectioned by the respective sectioning walls 32of the reinforcing member 30. Intervals L1 through L5 of the spaces S1through S5, which run along the vehicle transverse direction, arestructured so as to gradually become longer from the vehicle transversedirection inner side toward the vehicle transverse direction outer side.

Namely, the positions of the respective sectioning walls 32 are setappropriately such that the intervals L1 through L5 along the vehicletransverse direction of the five spaces S1 through S5 of the reinforcingmember 30 gradually become longer from the vehicle transverse directioninner side toward the vehicle transverse direction outer side.

Accordingly, in addition to the operation of the vehicle body lowerportion structure 10 relating to the above-described first embodiment,the rigidity of the reinforcing member 30 can be made to becomegradually higher from the vehicle transverse direction outer sideportion toward the vehicle transverse direction inner side portion.Accordingly, the deformation mode of the reinforcing member 30 towardthe vehicle transverse direction inner side due to the collision loadthat is inputted at the time of a side collision of the vehicle 12 canbe made gradually, and deformation of the vehicle cabin can be decreasedor prevented.

Note that, in the illustrated reinforcing member 30, the intervals L1through L5 of the spaces S1 through S5 gradually become longer from thevehicle transverse direction inner side toward the vehicle transversedirection outer side, but are not limited to this.

In the present embodiment, it suffices for there to be a structure inwhich at least the interval L1 of the space S1 that is at the vehicletransverse direction innermost side is shorter than any one of theintervals L2 through L5 of the other spaces S2 through S5. Accordingly,although not illustrated, for example, only the interval L1 of the spaceS1 may be structured to be shorter than the intervals L2 through L5along the vehicle transverse direction of the remaining spaces S2through S5, and the intervals L2 through L5 of these remaining spaces S2through S5 are structured to be the same.

Fourth Embodiment

The vehicle body lower portion structure 10 relating to a fourthembodiment is described next. Note that regions that are equivalent tothose of the above-described first embodiment through third embodimentare denoted by the same reference numerals, and detailed descriptionthereof (including description of common operation) is omitted asappropriate.

As shown in FIG. 6, in the vehicle body lower portion structure 10relating to the fourth embodiment, in the front view, the sectioningwalls 32 of the reinforcing member 30 are formed in bent shapes in whichthe vehicle body vertical direction central portions thereof are convexin the forms of obtuse angles toward the vehicle transverse directionouter side. Namely, the rigidity of the respective sectioning walls 32is improved with respect to load inputted from the vehicle transversedirection outer side.

Accordingly, in addition to operation of the vehicle body lower portionstructure 10 relating to the above-described first embodiment, when thereinforcing member 30 deforms so as to open wide at the time of a sidecollision of the vehicle 12, reaction force from the partitioning wall26 and the guide walls 28 is obtained even more effectively via theprojections 34. Accordingly, the buckling stress of the reinforcingmember 30 with respect to the collision load that is inputted at thetime of a side collision of the vehicle 12 can be increased even more.

Fifth Embodiment

The vehicle body lower portion structure 10 relating to a fifthembodiment is described next. Note that regions that are equivalent tothose of the above-described first embodiment through fourth embodimentare denoted by the same reference numerals, and detailed descriptionthereof (including description of common operation) is omitted asappropriate.

As shown in FIG. 7, in the vehicle body lower portion structure 10relating to the fifth embodiment, there is a structure in whichsectioning walls 33, which extend in the vehicle body longitudinaldirection with the vehicle body vertical direction being the normaldirection thereof, are further added at the substantially centralportions in the vehicle body vertical direction of the sectioning walls32 of the reinforcing member 30. Namely, this reinforcing member 30 hasthe sectioning walls 32, 33 that are in the form of a lattice.

Accordingly, in addition to the operation of the vehicle body lowerportion structure 10 relating to the above-described first embodiment,energy of the collision load that is inputted from the vehicletransverse direction outer side can be absorbed more effectively due to,in particular, the sectioning walls 33 plastically deforming. Namely, inaccordance with the fifth embodiment, the buckling stress of thereinforcing member 30 with respect to the collision load that isinputted at the time of a side collision of the vehicle 12 can beincreased even more.

Note that the sectioning walls 32, 33 that are in the form of a latticeat the reinforcing member 30 are not limited to the illustratedstructure. For example, although not illustrated, there may be astructure in which sectioning walls, which extend in the vehicle bodylongitudinal direction with the vehicle body vertical direction beingthe normal direction thereof, are further added at a predeterminedinterval in the vehicle body vertical direction with respect to thesectioning walls 33. Or, there may be a structure in which sectioningwalls, which extend in the vehicle body longitudinal direction with thevehicle transverse direction being the normal direction thereof, arefurther added at a predetermined interval in the vehicle transversedirection with respect to the sectioning walls 32.

Sixth Embodiment

The vehicle body lower portion structure 10 relating to a sixthembodiment is described next. Note that regions that are equivalent tothose of the above-described first embodiment through fifth embodimentare denoted by the same reference numerals, and detailed descriptionthereof (including description of common operation) is omitted asappropriate.

As shown in FIG. 8, in the vehicle body lower portion structure 10relating to the sixth embodiment, a lower partitioning wall 27, whichserves as the guide portion 25 and which divides the lower side chamberportion 24 into two parts up-and-down, is provided integrally with therocker 20, separately from the partitioning wall 26 that is providedintegrally between the upper side chamber portion 22 and the lower sidechamber portion 24. Namely, at the lower side chamber portion 24 of therocker 20, an intermediate chamber portion 23, which has an internaldimension that is substantially the same as the external dimension ofthe reinforcing member 30, is formed by the partitioning wall 26, theouter side wall 24T, a portion of the inner side wall 24N, and the lowerpartitioning wall 27.

Further, the reinforcing member 30 is inserted into the chamber of thisintermediate chamber portion 23 from the vehicle body front side or thevehicle body rear side. Namely, the reinforcing member 30 is insertedinto the intermediate chamber portion 23 while only the peak portions ofthe plural projections 34, which are formed integrally with the topsurface of the top wall 30U and the bottom surface of the bottom wall30D of the reinforcing member 30, are made to contact the bottom surfaceof the partitioning wall 26 and the top surface of the lowerpartitioning wall 27.

Accordingly, frictional resistance of the reinforcing member 30 withrespect to the bottom surface of the partitioning wall 26 and the topsurface of the lower partitioning wall 27 can be reduced as comparedwith a case in which the reinforcing member 30 is inserted into theintermediate chamber portion 23 while the top surface of the top wall30U and the bottom surface of the bottom wall 30D of the reinforcingmember 30 are made to contact the bottom surface of the partitioningwall 26 and the top surface of the lower partitioning wall 27.

Namely, in accordance with the sixth embodiment, even in a structure inwhich the reinforcing member 30 is inserted into and provided within theintermediate chamber portion 23, the frictional force at the time ofinserting the reinforcing member 30 into the intermediate chamberportion 23 can be reduced. Accordingly, the produceability of the rocker20 can be improved. Further, in accordance with the sixth embodiment,the buckling stress of the rocker 20 with respect to the collision loadthat is inputted at the time of a side collision of the vehicle 12 canbe increased by the lower partitioning wall 27. Therefore, deformationof the vehicle cabin can be reduced more.

Seventh Embodiment

Finally, the vehicle body lower portion structure 10 relating to aseventh embodiment is described. Note that regions that are equivalentto those of the above-described first embodiment through sixthembodiment are denoted by the same reference numerals, and detaileddescription thereof (including description of common operation) isomitted as appropriate.

As shown in FIG. 9, in the vehicle body lower portion structure 10relating to the seventh embodiment, the lower frame member is structuredby the rocker 20 that has a chamber structure and extends in the vehiclebody longitudinal direction, and an energy absorbing member 40 that isformed as a chamber that extends in the vehicle body longitudinaldirection and that is disposed at the vehicle body lower side of therocker 20 and the floor panel 18 (the floor panel 18 that is providedbetween the rocker 20 and the battery 14).

The energy absorbing member 40 is formed by extrusion molding of alight-weight metal material (e.g., an aluminum alloy), and, in the frontview, is sectioned into plural (e.g., two rows in the vehicle bodyvertical direction×five rows in the vehicle transverse direction)sections 44 by plural partitioning walls 42. Further, section 44U thatis formed at the upper portion of the vehicle transverse direction outerside is fastened by a bolt 46 and a weld nut 48 to a bottom wall 20D ofthe rocker 20. Section 44D that is formed at the lower portion of thevehicle transverse direction inner side is fastened by the bolt 46 andthe weld nut 48 to a bottom wall 36A of an under member 36 that isjoined to the bottom surface of the floor panel 18.

Note that work holes 44H for the insertion and screwing of the bolts 46are respectively formed in the partitioning wall 42 that is at thevehicle body lower side of the section 44U, and in a bottom wall 43 of asection 44T and the section 44D that are at the vehicle body lower sideof the section 44U. Further, the under member 36 is formed in the shapeof a hat in cross-section, and extends in the vehicle body longitudinaldirection. Moreover, an upper member 38, which is formed in the shape ofa hat in cross-section and extends in the vehicle body longitudinaldirection, is joined to the top surface of the floor panel 18.

Namely, the under member 36 and the upper member 38 are disposed so asto face one another vertically with the floor panel 18 therebetween.Further, a top wall 38A of this upper member 38 and an inner side wall20N that is disposed at the vehicle transverse direction inner side ofthe rocker 20 are joined by a connecting member 50. The vehicletransverse direction outer side end portion 18A of the floor panel 18 isbent toward the vehicle body upper side, and is joined to the inner sidewall 20N of the rocker 20.

Further, the reinforcing member 30 is provided by being inserted fromthe vehicle body front side or the vehicle body rear side into at leastone of the plural sections 44 of the energy absorbing member 40 (e.g., asection 44A that is formed at the lower portion of the vehicletransverse direction central portion). Namely, the reinforcing member 30is provided by being inserted into the section 44A while only the peakportions of the plural projections 34, which are formed integrally withthe top surface of the top wall 30U and the bottom surface of the bottomwall 30D of the reinforcing member 30, are made to contact the bottomsurface of a partitioning wall 42A and a top surface of a bottom wall43A that structure the section 44A.

Accordingly, the frictional resistance of the reinforcing member 30 withrespect to the partitioning wall 42A and the bottom wall 43A can bereduced as compared with a case in which the reinforcing member 30 isinserted into the section 44A while the top surface of the top wall 30Uand the bottom surface of the bottom wall 30D of the reinforcing member30 are made to contact the bottom surface of the partitioning wall 42Aand the top surface of the bottom wall 43A that structure the section44A. Namely, in accordance with the seventh aspect, even in a structurein which the reinforcing member 30 is inserted into and provided withinthe section 44A, the frictional force at the time of inserting thereinforcing member 30 into the section 44A can be reduced. Accordingly,the produceability of the energy absorbing member 40 can be improved.

Further, in accordance with this seventh embodiment, the buckling stressof the lower frame member, i.e., the rocker 20 and the energy absorbingmember 40, with respect to the collision load that is inputted at thetime of a side collision of the vehicle 12 can be increased by theconnecting member 50 and the reinforcing member 30 respectively.Accordingly, deformation of the vehicle cabin can be further suppressedat the time of a side collision of the vehicle 12.

Note that the section 44 in which the reinforcing member 30 is providedis not limited to the illustrated section 44A. Further, it suffices forthe energy absorbing member 40 to have at least one section 44 in whichthe reinforcing member 30 is provided, and the energy absorbing member40 itself as well is not limited to the illustrated shape. Further, asin the above-described first embodiment through sixth embodiment, thereinforcing member 30 may be provided within the chamber of the rocker20. Namely, in the seventh embodiment, it suffices to provide thereinforcing member 30 at least in the section 44 of the energy absorbingmember 40.

The vehicle body lower portion structures 10 relating to the presentembodiments have been described above on the basis of the drawings.However, the vehicle body lower portion structures 10 relating to thepresent embodiments are not limited to the illustrated structures, andthe designs thereof can be changed appropriately within a scope of thepresent claims. For example, the number of the sectioning walls 32 isnot limited to a plural number, and may be one.

Further, although the respective projections 34 are formed so as to becontinuous in the vehicle body longitudinal direction, the projectionsare not limited to this and may be formed discontinuously in the vehiclebody longitudinal direction. Further, the guide walls 28 are not limitedto structures that are formed integrally with the rocker 20. Forexample, the guide walls may be structured so as to be joined by anadhesive or rivets or the like to the inner surface of the outer sidewall 24T and the inner surface of the inner side wall 24N of the lowerside chamber portion 24 of the rocker 20.

Further, the light-weight metal material is not limited to an aluminumalloy. Moreover, the reinforcing member 30 is not limited to a structurethat is formed of a light-weight metal material, and may be formed of,for example, a relatively hard resin material (a so-called engineeringplastic) such as polycarbonate (PC) or the like.

Further, there may be a structure in which the first embodiment throughthe seventh embodiment are combined appropriately. For example, thestructure of the reinforcing member 30 in the third embodiment, i.e.,the structure in which the intervals L1 through L5 along the vehicletransverse direction of the plural (e.g., five) spaces S1 through S5gradually become longer from the vehicle transverse direction inner sidetoward the vehicle transverse direction outer side due to the sectioningwalls 32 that are shaped as flat plates, may be applied to thereinforcing member 30 that has the mountain-shaped sectioning walls 32of the fourth embodiment.

What is claimed is:
 1. A vehicle body lower portion structure,comprising: a rocker formed as a chamber that extends in a vehicle bodyfront-rear direction; a floor panel joined to the rocker; an undermember joined to the floor panel at an inner side, in a vehicle bodytransverse direction, of the rocker; an energy absorbing member formedas a chamber that extends in the vehicle body front-rear direction, theenergy absorbing member being joined to a lower wall of the rocker andjoined to a lower wall of the under member; and a battery configured tobe disposed at an inner side, in the vehicle body transverse direction,of the under member and the energy absorbing member, wherein the energyabsorbing member is divided into a plurality of sections by a pluralityof partitioning walls as viewed in the vehicle body front-reardirection, and wherein the under member is formed in the shape of a hatin cross-section, extends in the vehicle body front-rear direction, andat least one of the plurality of sections of the energy absorbing memberis disposed so as to oppose each side wall of the under member.
 2. Thevehicle body lower portion structure of claim 1, wherein at least aportion of the energy absorbing member is disposed between the rockerand the under member, in a vehicle body vertical direction and in thevehicle body transverse direction.
 3. The vehicle body lower portionstructure of claim 1, wherein a reinforcement member is disposed withinone of the plurality of sections of the energy absorbing member.
 4. Thevehicle body lower portion structure of claim 1, further comprising: anupper member disposed above the under member with the floor paneldisposed therebetween; and a connecting member joining the upper memberand an inner side wall that is disposed at an inner side, in the vehicletransverse direction, of the rocker.
 5. The vehicle body lower portionstructure of claim 1, further comprising a battery frame, wherein: thebattery is configured to be installed at the battery frame, and thebattery frame is joined to the energy absorbing member.
 6. A vehiclebody lower portion structure, comprising: a rocker formed as a chamberthat extends in a vehicle body front-rear direction; a floor paneljoined to the rocker; an under member joined to the floor panel at aninner side, in a vehicle body transverse direction, of the rocker; anenergy absorbing member formed as a chamber that extends in the vehiclebody front-rear direction, the energy absorbing member being joined to alower wall of the rocker and joined to a lower wall of the under member;and a battery configured to be disposed at an inner side, in the vehiclebody transverse direction, of the under member and the energy absorbingmember wherein the energy absorbing member is divided into a pluralityof sections by a plurality of partitioning walls as viewed in thevehicle body front-rear direction, wherein a reinforcement member isdisposed within one of the plurality of sections of the energy absorbingmember, and wherein the reinforcement member is disposed between therocker and the under member in the vehicle body transverse direction. 7.The vehicle body lower portion structure of claim 6, wherein at least aportion of the energy absorbing member is disposed between the rockerand the under member, in a vehicle body vertical direction and in thevehicle body transverse direction.
 8. The vehicle body lower portionstructure of claim 6, further comprising: an upper member disposed abovethe under member with the floor panel disposed therebetween; and aconnecting member joining the upper member and an inner side wall thatis disposed at an inner side, in the vehicle transverse direction, ofthe rocker.
 9. The vehicle body lower portion structure of claim 6,further comprising a battery frame, wherein: the battery is configuredto be installed at the battery frame, and the battery frame is joined tothe energy absorbing member.
 10. A vehicle body lower portion structure,comprising: a rocker formed as a chamber that extends in a vehicle bodyfront-rear direction; a floor panel joined to the rocker; an undermember joined to the floor panel at an inner side, in a vehicle bodytransverse direction, of the rocker; an energy absorbing member formedas a chamber that extends in the vehicle body front-rear direction, theenergy absorbing member being joined to a lower wall of the rocker andjoined to a lower wall of the under member; and a battery configured tobe disposed at an inner side, in the vehicle body transverse direction,of the under member and the energy absorbing member, wherein the energyabsorbing member is divided into a plurality of sections by a pluralityof partitioning walls as viewed in the vehicle body front-reardirection, wherein a reinforcement member is disposed within one of theplurality of sections of the energy absorbing member, and wherein thereinforcing member is formed as a rectangular chamber extending in thevehicle body front-rear direction, and has a plurality of projectionsprovided at a top surface of a top wall, and a bottom surface of abottom wall, of the reinforcing member, wherein peak portions of theplurality of the projections are configured to contact an upper surfaceof a bottom wall, and a lower surface of a top wall, of the one of theplurality of sections of the energy absorbing member.
 11. The vehiclebody lower portion structure of claim 10, wherein a plurality ofsectioning walls, which partition an interior of the chamber of thereinforcing member, are formed integrally with the reinforcing member.12. The vehicle body lower portion structure of claim 10, wherein atleast a portion of the energy absorbing member is disposed between therocker and the under member, in a vehicle body vertical direction and inthe vehicle body transverse direction.
 13. The vehicle body lowerportion structure of claim 10, further comprising: an upper memberdisposed above the under member with the floor panel disposedtherebetween; and a connecting member joining the upper member and aninner side wall that is disposed at an inner side, in the vehicletransverse direction, of the rocker.
 14. The vehicle body lower portionstructure of claim 10, further comprising a battery frame, wherein: thebattery is configured to be installed at the battery frame, and thebattery frame is joined to the energy absorbing member.